This invention relates generally to building structures and particularly to building structures for industrial or commercial use.
The building structure of the present invention has universal application and may be built on any raw land, unused or formerly used, filled or contaminated and improved by suspending a dead level building above it which is of improved construction, faster and less costly to build, and without requiring penetration of the soil except for utilities.
Once a building site is selected, vegetation is removed, and the soil cut or filled to an established sub-grade elevation. A few inches of preferred 21A grade aggregate is preferably spread over the area where the building is to be erected, to facilitate squeezing out moisture and compacting the soil to develop optimum bearing capacity by heavy roller vibration, and/or dynamic compaction. Reinforced concrete column footings are then installed so that the concrete floor of the building will overlie the footings.
The footings preferably have extended high-strength anchor bolts that are threaded and double-nutted to suspend the entire structure several inches, sufficient to provide for any settlement adjustment and to maintain a level roof and facilitate the remainder of the construction procedure.
Upon completion of the column footings, the entire building site is graded to allow for the aggregate and also for an asphalt sub-flooring preferably at approximately the column footing elevations. The perimeter of the sub-flooring is preferably sloped for drainage.
The aggregate and the overlaid asphalt sub-flooring provide an impervious cap to seal off against contamination by preventing vapors and gases from entering the building and qualifying for approval by the Department of Environmental Quality (DEQ).
The asphalt sub-floor, before the finished concrete is overlaid, provides a useful storage and mobile working surface for receiving building materials and equipment which will be needed in the construction of the building. It therefore should not be necessary to store such materials and equipment on the bare ground outside of the building site where they will pick up mud and require to be cleaned before they can be installed in the building.
The building construction includes a roof which preferably has a flat horizontal or level surface surrounded by a border frame for the retention of water to a maximum depth of about three inches. Level roofs are required in many cities. Water is intended to be retained on this roof and by evaporation to have a cooling effect within the building and thereby reduce the load on air conditioning equipment in the building. A one-inch depth of water is sufficient for cooling by evaporation. An additional two inches of capacity is desirable to accommodate flash flood water which otherwise could produce back-up in undersized sewer systems.
It is an object of this invention to provide a building structure having the foregoing features and capabilities.
Other objects, features and advantages will become more apparent as the following description proceeds, especially when considered with the accompanying drawings and claims.